1. Field of the Invention
The present invention relates to a unit for bending pieces of metal sheet.
The present invention also relates to a device for manipulating pieces of metal sheet for a bending press.
2. Description of the Prior Art
An Italian Patent Application No. 67224-A/88A filed on Mar. 15, 1988 (having a counterpart U.S. Pat. No. 5,042,287) discloses a unit for bending pieces of metal sheet, and a device for manipulating pieces of metal sheet for a bending press having a punch and a die.
The unit for bending pieces of metal sheet includes:
a device for manipulating pieces of metal sheet, provided with gripping means for gripping a piece of metal sheet and manipulating it during the automatic operating cycle, and
an auxiliary gripping device for turning a piece of metal sheet through 180.degree. about an axis perpendicular to the bending line, comprising at least one pair of grippers mounted for rotation about the said axis perpendicular to the bending line and movable between a first position in which they are situated in a manipulation space in front of the loading region of the press and a second position in which they are situated outside the manipulation space.
The device for manipulating pieces of metal sheet for a bending press having a punch and a die which cooperate each other along a bending line includes:
a base structure slidable along a fixed guide beam parallel to the bending line and carrying a pair of gripping members for gripping a piece of metal sheet and for moving it during an automatic bending cycle, and
an auxiliary gripping device for turning a piece of metal sheet over about an axis perpendicular to the bending line, including at least one pair of grippers mounted for rotation about the axis perpendicular to the bending line.
In the bending unit and the manipulator device described in the above mentioned Italian Patent Application, the auxiliary gripping device is fixed to the floor in front of the press, on the opposite side of the manipulator device. This arrangement means that the auxiliary gripping device constitutes an obstacle when it is necessary for the press to be used manually, that is, without the use of the manipulator device, or when access to the press is required for maintenance.